X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=drivers%2Fchar%2Fmem.c;h=f833f97564e82d742d6884d8255e056d4a79dfd0;hb=97bf2856c6014879bd04983a3e9dfcdac1e7fe85;hp=840a0afaeb1b2735e564c3a212cf45b52f6f0d49;hpb=6a77f38946aaee1cd85eeec6cf4229b204c15071;p=linux-2.6.git diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 840a0afae..f833f9756 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -8,7 +8,6 @@ * Shared /dev/zero mmaping support, Feb 2000, Kanoj Sarcar */ -#include #include #include #include @@ -20,9 +19,14 @@ #include #include #include -#include #include #include +#include +#include +#include +#include +#include +#include #include #include @@ -31,9 +35,21 @@ # include #endif -#if defined(CONFIG_S390_TAPE) && defined(CONFIG_S390_TAPE_CHAR) -extern void tapechar_init(void); -#endif +static inline int range_is_allowed(unsigned long from, unsigned long to) +{ + unsigned long cursor; + + cursor = from >> PAGE_SHIFT; + while ((cursor << PAGE_SHIFT) < to) { + if (!devmem_is_allowed(cursor)) { + printk ("Program %s tried to read /dev/mem between %lx->%lx.\n", + current->comm, from, to); + return 0; + } + cursor++; + } + return 1; +} /* * Architectures vary in how they handle caching for addresses @@ -76,14 +92,6 @@ static inline int uncached_access(struct file *file, unsigned long addr) * On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases. */ return !(efi_mem_attributes(addr) & EFI_MEMORY_WB); -#elif defined(CONFIG_PPC64) - /* On PPC64, we always do non-cacheable access to the IO hole and - * cacheable elsewhere. Cache paradox can checkstop the CPU and - * the high_memory heuristic below is wrong on machines with memory - * above the IO hole... Ah, and of course, XFree86 doesn't pass - * O_SYNC when mapping us to tap IO space. Surprised ? - */ - return !page_is_ram(addr >> PAGE_SHIFT); #else /* * Accessing memory above the top the kernel knows about or through a file pointer @@ -96,54 +104,21 @@ static inline int uncached_access(struct file *file, unsigned long addr) } #ifndef ARCH_HAS_VALID_PHYS_ADDR_RANGE -static inline int valid_phys_addr_range(unsigned long addr, size_t *count) +static inline int valid_phys_addr_range(unsigned long addr, size_t count) { - unsigned long end_mem; - - end_mem = __pa(high_memory); - if (addr >= end_mem) + if (addr + count > __pa(high_memory)) return 0; - if (*count > end_mem - addr) - *count = end_mem - addr; - return 1; } -#endif -static ssize_t do_write_mem(void *p, unsigned long realp, - const char __user * buf, size_t count, loff_t *ppos) +static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) { - ssize_t written; - unsigned long copied; - - written = 0; -#if defined(__sparc__) || (defined(__mc68000__) && defined(CONFIG_MMU)) - /* we don't have page 0 mapped on sparc and m68k.. */ - if (realp < PAGE_SIZE) { - unsigned long sz = PAGE_SIZE-realp; - if (sz > count) sz = count; - /* Hmm. Do something? */ - buf+=sz; - p+=sz; - count-=sz; - written+=sz; - } -#endif - copied = copy_from_user(p, buf, count); - if (copied) { - ssize_t ret = written + (count - copied); - - if (ret) - return ret; - return -EFAULT; - } - written += count; - *ppos += written; - return written; + return 1; } +#endif - +#ifndef ARCH_HAS_DEV_MEM /* * This funcion reads the *physical* memory. The f_pos points directly to the * memory location. @@ -152,15 +127,16 @@ static ssize_t read_mem(struct file * file, char __user * buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; - ssize_t read; + ssize_t read, sz; + char *ptr; - if (!valid_phys_addr_range(p, &count)) + if (!valid_phys_addr_range(p, count)) return -EFAULT; read = 0; -#if defined(__sparc__) || (defined(__mc68000__) && defined(CONFIG_MMU)) +#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED /* we don't have page 0 mapped on sparc and m68k.. */ if (p < PAGE_SIZE) { - unsigned long sz = PAGE_SIZE-p; + sz = PAGE_SIZE - p; if (sz > count) sz = count; if (sz > 0) { @@ -173,9 +149,35 @@ static ssize_t read_mem(struct file * file, char __user * buf, } } #endif - if (copy_to_user(buf, __va(p), count)) - return -EFAULT; - read += count; + + while (count > 0) { + /* + * Handle first page in case it's not aligned + */ + if (-p & (PAGE_SIZE - 1)) + sz = -p & (PAGE_SIZE - 1); + else + sz = PAGE_SIZE; + + sz = min_t(unsigned long, sz, count); + + /* + * On ia64 if a page has been mapped somewhere as + * uncached, then it must also be accessed uncached + * by the kernel or data corruption may occur + */ + ptr = xlate_dev_mem_ptr(p); + + if (!range_is_allowed(p, p+count)) + return -EPERM; + if (copy_to_user(buf, ptr, sz)) + return -EFAULT; + buf += sz; + p += sz; + count -= sz; + read += sz; + } + *ppos += read; return read; } @@ -184,33 +186,186 @@ static ssize_t write_mem(struct file * file, const char __user * buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; + ssize_t written, sz; + unsigned long copied; + void *ptr; - if (!valid_phys_addr_range(p, &count)) + if (!valid_phys_addr_range(p, count)) return -EFAULT; - return do_write_mem(__va(p), p, buf, count, ppos); + + written = 0; + +#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED + /* we don't have page 0 mapped on sparc and m68k.. */ + if (p < PAGE_SIZE) { + unsigned long sz = PAGE_SIZE - p; + if (sz > count) + sz = count; + /* Hmm. Do something? */ + buf += sz; + p += sz; + count -= sz; + written += sz; + } +#endif + + while (count > 0) { + /* + * Handle first page in case it's not aligned + */ + if (-p & (PAGE_SIZE - 1)) + sz = -p & (PAGE_SIZE - 1); + else + sz = PAGE_SIZE; + + sz = min_t(unsigned long, sz, count); + + /* + * On ia64 if a page has been mapped somewhere as + * uncached, then it must also be accessed uncached + * by the kernel or data corruption may occur + */ + ptr = xlate_dev_mem_ptr(p); + + if (!range_is_allowed(ptr, ptr+sz)) + return -EPERM; + copied = copy_from_user(ptr, buf, sz); + if (copied) { + written += sz - copied; + if (written) + break; + return -EFAULT; + } + buf += sz; + p += sz; + count -= sz; + written += sz; + } + + *ppos += written; + return written; } +#endif -static int mmap_mem(struct file * file, struct vm_area_struct * vma) +#ifndef __HAVE_PHYS_MEM_ACCESS_PROT +static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, + unsigned long size, pgprot_t vma_prot) { #ifdef pgprot_noncached - unsigned long offset = vma->vm_pgoff << PAGE_SHIFT; - int uncached; + unsigned long offset = pfn << PAGE_SHIFT; - uncached = uncached_access(file, offset); - if (uncached) - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + if (uncached_access(file, offset)) + return pgprot_noncached(vma_prot); +#endif + return vma_prot; +} #endif +#ifndef CONFIG_MMU +static unsigned long get_unmapped_area_mem(struct file *file, + unsigned long addr, + unsigned long len, + unsigned long pgoff, + unsigned long flags) +{ + if (!valid_mmap_phys_addr_range(pgoff, len)) + return (unsigned long) -EINVAL; + return pgoff << PAGE_SHIFT; +} + +/* can't do an in-place private mapping if there's no MMU */ +static inline int private_mapping_ok(struct vm_area_struct *vma) +{ + return vma->vm_flags & VM_MAYSHARE; +} +#else +#define get_unmapped_area_mem NULL + +static inline int private_mapping_ok(struct vm_area_struct *vma) +{ + return 1; +} +#endif + +static int mmap_mem(struct file * file, struct vm_area_struct * vma) +{ + size_t size = vma->vm_end - vma->vm_start; + + if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) + return -EINVAL; + + if (!private_mapping_ok(vma)) + return -ENOSYS; + + vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff, + size, + vma->vm_page_prot); + /* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */ if (remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff, - vma->vm_end-vma->vm_start, + size, vma->vm_page_prot)) return -EAGAIN; return 0; } +static int mmap_kmem(struct file * file, struct vm_area_struct * vma) +{ + unsigned long pfn; + + /* Turn a kernel-virtual address into a physical page frame */ + pfn = __pa((u64)vma->vm_pgoff << PAGE_SHIFT) >> PAGE_SHIFT; + + /* + * RED-PEN: on some architectures there is more mapped memory + * than available in mem_map which pfn_valid checks + * for. Perhaps should add a new macro here. + * + * RED-PEN: vmalloc is not supported right now. + */ + if (!pfn_valid(pfn)) + return -EIO; + + vma->vm_pgoff = pfn; + return mmap_mem(file, vma); +} + +#ifdef CONFIG_CRASH_DUMP +/* + * Read memory corresponding to the old kernel. + */ +static ssize_t read_oldmem(struct file *file, char __user *buf, + size_t count, loff_t *ppos) +{ + unsigned long pfn, offset; + size_t read = 0, csize; + int rc = 0; + + while (count) { + pfn = *ppos / PAGE_SIZE; + if (pfn > saved_max_pfn) + return read; + + offset = (unsigned long)(*ppos % PAGE_SIZE); + if (count > PAGE_SIZE - offset) + csize = PAGE_SIZE - offset; + else + csize = count; + + rc = copy_oldmem_page(pfn, buf, csize, offset, 1); + if (rc < 0) + return rc; + buf += csize; + *ppos += csize; + read += csize; + count -= csize; + } + return read; +} +#endif + extern long vread(char *buf, char *addr, unsigned long count); extern long vwrite(char *buf, char *addr, unsigned long count); @@ -221,33 +376,57 @@ static ssize_t read_kmem(struct file *file, char __user *buf, size_t count, loff_t *ppos) { unsigned long p = *ppos; - ssize_t read = 0; - ssize_t virtr = 0; + ssize_t low_count, read, sz; char * kbuf; /* k-addr because vread() takes vmlist_lock rwlock */ - + + return -EPERM; + + read = 0; if (p < (unsigned long) high_memory) { - read = count; + low_count = count; if (count > (unsigned long) high_memory - p) - read = (unsigned long) high_memory - p; + low_count = (unsigned long) high_memory - p; -#if defined(__sparc__) || (defined(__mc68000__) && defined(CONFIG_MMU)) +#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED /* we don't have page 0 mapped on sparc and m68k.. */ - if (p < PAGE_SIZE && read > 0) { + if (p < PAGE_SIZE && low_count > 0) { size_t tmp = PAGE_SIZE - p; - if (tmp > read) tmp = read; + if (tmp > low_count) tmp = low_count; if (clear_user(buf, tmp)) return -EFAULT; buf += tmp; p += tmp; - read -= tmp; + read += tmp; + low_count -= tmp; count -= tmp; } #endif - if (copy_to_user(buf, (char *)p, read)) - return -EFAULT; - p += read; - buf += read; - count -= read; + while (low_count > 0) { + /* + * Handle first page in case it's not aligned + */ + if (-p & (PAGE_SIZE - 1)) + sz = -p & (PAGE_SIZE - 1); + else + sz = PAGE_SIZE; + + sz = min_t(unsigned long, sz, low_count); + + /* + * On ia64 if a page has been mapped somewhere as + * uncached, then it must also be accessed uncached + * by the kernel or data corruption may occur + */ + kbuf = xlate_dev_kmem_ptr((char *)p); + + if (copy_to_user(buf, kbuf, sz)) + return -EFAULT; + buf += sz; + p += sz; + read += sz; + low_count -= sz; + count -= sz; + } } if (count > 0) { @@ -268,82 +447,23 @@ static ssize_t read_kmem(struct file *file, char __user *buf, } count -= len; buf += len; - virtr += len; - p += len; - } - free_page((unsigned long)kbuf); - } - *ppos = p; - return virtr + read; -} - -/* - * This function writes to the *virtual* memory as seen by the kernel. - */ -static ssize_t write_kmem(struct file * file, const char __user * buf, - size_t count, loff_t *ppos) -{ - unsigned long p = *ppos; - ssize_t wrote = 0; - ssize_t virtr = 0; - ssize_t written; - char * kbuf; /* k-addr because vwrite() takes vmlist_lock rwlock */ - - if (p < (unsigned long) high_memory) { - - wrote = count; - if (count > (unsigned long) high_memory - p) - wrote = (unsigned long) high_memory - p; - - written = do_write_mem((void*)p, p, buf, wrote, ppos); - if (written != wrote) - return written; - wrote = written; - p += wrote; - buf += wrote; - count -= wrote; - } - - if (count > 0) { - kbuf = (char *)__get_free_page(GFP_KERNEL); - if (!kbuf) - return wrote ? wrote : -ENOMEM; - while (count > 0) { - int len = count; - - if (len > PAGE_SIZE) - len = PAGE_SIZE; - if (len) { - written = copy_from_user(kbuf, buf, len); - if (written) { - ssize_t ret; - - free_page((unsigned long)kbuf); - ret = wrote + virtr + (len - written); - return ret ? ret : -EFAULT; - } - } - len = vwrite(kbuf, (char *)p, len); - count -= len; - buf += len; - virtr += len; + read += len; p += len; } free_page((unsigned long)kbuf); } - *ppos = p; - return virtr + wrote; + return read; } -#if defined(CONFIG_ISA) || !defined(__mc68000__) +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) static ssize_t read_port(struct file * file, char __user * buf, size_t count, loff_t *ppos) { unsigned long i = *ppos; char __user *tmp = buf; - if (verify_area(VERIFY_WRITE,buf,count)) + if (!access_ok(VERIFY_WRITE, buf, count)) return -EFAULT; while (count-- > 0 && i < 65536) { if (__put_user(inb(i),tmp) < 0) @@ -361,12 +481,15 @@ static ssize_t write_port(struct file * file, const char __user * buf, unsigned long i = *ppos; const char __user * tmp = buf; - if (verify_area(VERIFY_READ,buf,count)) + if (!access_ok(VERIFY_READ,buf,count)) return -EFAULT; while (count-- > 0 && i < 65536) { char c; - if (__get_user(c, tmp)) + if (__get_user(c, tmp)) { + if (tmp > buf) + break; return -EFAULT; + } outb(c,i); i++; tmp++; @@ -388,6 +511,18 @@ static ssize_t write_null(struct file * file, const char __user * buf, return count; } +static int pipe_to_null(struct pipe_inode_info *info, struct pipe_buffer *buf, + struct splice_desc *sd) +{ + return sd->len; +} + +static ssize_t splice_write_null(struct pipe_inode_info *pipe,struct file *out, + loff_t *ppos, size_t len, unsigned int flags) +{ + return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null); +} + #ifdef CONFIG_MMU /* * For fun, we are using the MMU for this. @@ -415,7 +550,8 @@ static inline size_t read_zero_pagealigned(char __user * buf, size_t size) count = size; zap_page_range(vma, addr, count, NULL); - zeromap_page_range(vma, addr, count, PAGE_COPY); + if (zeromap_page_range(vma, addr, count, PAGE_COPY)) + break; size -= count; buf += count; @@ -482,11 +618,14 @@ out: static int mmap_zero(struct file * file, struct vm_area_struct * vma) { + int err; + if (vma->vm_flags & VM_SHARED) return shmem_zero_setup(vma); - if (zeromap_page_range(vma, vma->vm_start, vma->vm_end - vma->vm_start, vma->vm_page_prot)) - return -EAGAIN; - return 0; + err = zeromap_page_range(vma, vma->vm_start, + vma->vm_end - vma->vm_start, vma->vm_page_prot); + BUG_ON(err == -EEXIST); + return err; } #else /* CONFIG_MMU */ static ssize_t read_zero(struct file * file, char * buf, @@ -543,7 +682,7 @@ static loff_t memory_lseek(struct file * file, loff_t offset, int orig) { loff_t ret; - down(&file->f_dentry->d_inode->i_sem); + mutex_lock(&file->f_path.dentry->d_inode->i_mutex); switch (orig) { case 0: file->f_pos = offset; @@ -558,7 +697,7 @@ static loff_t memory_lseek(struct file * file, loff_t offset, int orig) default: ret = -EINVAL; } - up(&file->f_dentry->d_inode->i_sem); + mutex_unlock(&file->f_path.dentry->d_inode->i_mutex); return ret; } @@ -567,38 +706,44 @@ static int open_port(struct inode * inode, struct file * filp) return capable(CAP_SYS_RAWIO) ? 0 : -EPERM; } -#define mmap_kmem mmap_mem #define zero_lseek null_lseek #define full_lseek null_lseek #define write_zero write_null #define read_full read_zero #define open_mem open_port #define open_kmem open_mem +#define open_oldmem open_mem -static struct file_operations mem_fops = { +#ifndef ARCH_HAS_DEV_MEM +static const struct file_operations mem_fops = { .llseek = memory_lseek, .read = read_mem, .write = write_mem, .mmap = mmap_mem, .open = open_mem, + .get_unmapped_area = get_unmapped_area_mem, }; +#else +extern struct file_operations mem_fops; +#endif -static struct file_operations kmem_fops = { +static const struct file_operations kmem_fops = { .llseek = memory_lseek, .read = read_kmem, - .write = write_kmem, .mmap = mmap_kmem, .open = open_kmem, + .get_unmapped_area = get_unmapped_area_mem, }; -static struct file_operations null_fops = { +static const struct file_operations null_fops = { .llseek = null_lseek, .read = read_null, .write = write_null, + .splice_write = splice_write_null, }; -#if defined(CONFIG_ISA) || !defined(__mc68000__) -static struct file_operations port_fops = { +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) +static const struct file_operations port_fops = { .llseek = memory_lseek, .read = read_port, .write = write_port, @@ -606,24 +751,39 @@ static struct file_operations port_fops = { }; #endif -static struct file_operations zero_fops = { +static const struct file_operations zero_fops = { .llseek = zero_lseek, .read = read_zero, .write = write_zero, .mmap = mmap_zero, }; -static struct file_operations full_fops = { +/* + * capabilities for /dev/zero + * - permits private mappings, "copies" are taken of the source of zeros + */ +static struct backing_dev_info zero_bdi = { + .capabilities = BDI_CAP_MAP_COPY, +}; + +static const struct file_operations full_fops = { .llseek = full_lseek, .read = read_full, .write = write_full, }; +#ifdef CONFIG_CRASH_DUMP +static const struct file_operations oldmem_fops = { + .read = read_oldmem, + .open = open_oldmem, +}; +#endif + static ssize_t kmsg_write(struct file * file, const char __user * buf, size_t count, loff_t *ppos) { char *tmp; - int ret; + ssize_t ret; tmp = kmalloc(count + 1, GFP_KERNEL); if (tmp == NULL) @@ -632,12 +792,15 @@ static ssize_t kmsg_write(struct file * file, const char __user * buf, if (!copy_from_user(tmp, buf, count)) { tmp[count] = 0; ret = printk("%s", tmp); + if (ret > count) + /* printk can add a prefix */ + ret = count; } kfree(tmp); return ret; } -static struct file_operations kmsg_fops = { +static const struct file_operations kmsg_fops = { .write = kmsg_write, }; @@ -646,19 +809,24 @@ static int memory_open(struct inode * inode, struct file * filp) switch (iminor(inode)) { case 1: filp->f_op = &mem_fops; + filp->f_mapping->backing_dev_info = + &directly_mappable_cdev_bdi; break; case 2: filp->f_op = &kmem_fops; + filp->f_mapping->backing_dev_info = + &directly_mappable_cdev_bdi; break; case 3: filp->f_op = &null_fops; break; -#if defined(CONFIG_ISA) || !defined(__mc68000__) +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) case 4: filp->f_op = &port_fops; break; #endif case 5: + filp->f_mapping->backing_dev_info = &zero_bdi; filp->f_op = &zero_fops; break; case 7: @@ -673,6 +841,11 @@ static int memory_open(struct inode * inode, struct file * filp) case 11: filp->f_op = &kmsg_fops; break; +#ifdef CONFIG_CRASH_DUMP + case 12: + filp->f_op = &oldmem_fops; + break; +#endif default: return -ENXIO; } @@ -681,7 +854,7 @@ static int memory_open(struct inode * inode, struct file * filp) return 0; } -static struct file_operations memory_fops = { +static const struct file_operations memory_fops = { .open = memory_open, /* just a selector for the real open */ }; @@ -689,12 +862,11 @@ static const struct { unsigned int minor; char *name; umode_t mode; - struct file_operations *fops; + const struct file_operations *fops; } devlist[] = { /* list of minor devices */ {1, "mem", S_IRUSR | S_IWUSR | S_IRGRP, &mem_fops}, - {2, "kmem", S_IRUSR | S_IWUSR | S_IRGRP, &kmem_fops}, {3, "null", S_IRUGO | S_IWUGO, &null_fops}, -#if defined(CONFIG_ISA) || !defined(__mc68000__) +#if (defined(CONFIG_ISA) || defined(CONFIG_PCI)) && !defined(__mc68000__) {4, "port", S_IRUSR | S_IWUSR | S_IRGRP, &port_fops}, #endif {5, "zero", S_IRUGO | S_IWUGO, &zero_fops}, @@ -702,9 +874,12 @@ static const struct { {8, "random", S_IRUGO | S_IWUSR, &random_fops}, {9, "urandom", S_IRUGO | S_IWUSR, &urandom_fops}, {11,"kmsg", S_IRUGO | S_IWUSR, &kmsg_fops}, +#ifdef CONFIG_CRASH_DUMP + {12,"oldmem", S_IRUSR | S_IWUSR | S_IRGRP, &oldmem_fops}, +#endif }; -static struct class_simple *mem_class; +static struct class *mem_class; static int __init chr_dev_init(void) { @@ -713,15 +888,12 @@ static int __init chr_dev_init(void) if (register_chrdev(MEM_MAJOR,"mem",&memory_fops)) printk("unable to get major %d for memory devs\n", MEM_MAJOR); - mem_class = class_simple_create(THIS_MODULE, "mem"); - for (i = 0; i < ARRAY_SIZE(devlist); i++) { - class_simple_device_add(mem_class, - MKDEV(MEM_MAJOR, devlist[i].minor), - NULL, devlist[i].name); - devfs_mk_cdev(MKDEV(MEM_MAJOR, devlist[i].minor), - S_IFCHR | devlist[i].mode, devlist[i].name); - } - + mem_class = class_create(THIS_MODULE, "mem"); + for (i = 0; i < ARRAY_SIZE(devlist); i++) + device_create(mem_class, NULL, + MKDEV(MEM_MAJOR, devlist[i].minor), + devlist[i].name); + return 0; }